Method of corner cutting envelope blanks



June 27, 1967 v. E. HEYWOOD METHOD OF CORNER CUTTING ENVE LOPE BLANKS 2 Sheets-Sheet 1 Filed March 5, 1965 lNl/ENTOR VINCENT E. HEVWOOD AGENT V. E. HEYWOOD METHOD OF CORNER CUTTING ENVELOP June 27, 1967 E BLANKS 2 Sheets-Sheet 2 Filed March 3, 1965 United States Patent 3,327,576 METHOD OF CORNER CUTTING ENVELOPE BLANKS Vincent E. Heywood, 40 Massachusetts Ave., Worcester, Mass. 01602 Filed Mar. 3, 1965, Ser. No. 436,805 3 Claims. (CI. 83-13) This invention relates generally to the manufacture of envelopes, and more specifically, to a method of cutting notches from the edges of flat envelope blanks to make them ready for folding.

In the manufacture of so-called diagonal seam envelopes, flat blanks are generally folded to define a substantially rectangular front panel having generally triangular flaps extending from the edges of the front panel, foldable into overlapping relation to form a back panel. At each of the corners of the front panel, between the adjacent flaps, a generally triangular notch having its apex at a corner of the front panel, and its base extending along the edge of the blank, is removed to provide for the easy and effective folding of the blank into a completed envelope. Removal of the notches allows overlapping of the flaps to form the back panel, while at the same time, assuring that each of the folds will only be through one thickness of paper.

Whether the blanks are die cut or web cut, the notches in the edges are necessary for the proper forming of the envelopes. In the die cut blanks, the notches are generally formed by using a die having the shape required to extract, or form, the notches. However, in the manufacture of envelopes where the blank is cut from the end of the web, the blank is rhombic, or diamond shape, and the edges are straight. One of the first operations to be performed on the blank is the cutting of the aforementioned triangular notches in the four sides of the blank. For instance, in my US Patent No. 2,696,255 Blank Forming Method and Mechanism for Envelope Making Machines issued Dec. 7, 1954, immediately after the rhombic shaped blanks are severed from the end of the traveling web, and the direction of travel is changed so that the blanks travel in a direction parallel to a diagonal, the blanks are scored and the triangular notches are cut.

As described in my aforementioned patent, the blanks are fed successively through two pairs of corner-cutters, each pair being mounted on separate shafts, and which rotate about an axis perpendicular to the direction of blank feed. One pair of cutters cuts the notches in leading edges of blanks, and the other pair cuts the notches in the trailing edges of the blanks as they are fed through the machine. Also, in this machine, the corner cutters are mounted on the same shaft as the blank-forwarding rolls, and the speed of the cutters must therefore be the same as the speed of the passing blanks. Each of the four cutters must be angularly adjusted on its carrier shaft as well as laterally, or transversely adjusted to act on the envelope blanks at the correct location.

It is an object of the present invention to provide a simpler and more practical method of cutting the notches from the edges of the envelopes than has been possible in the past.

It is a further object of this invention to provide a method of cutting the notches in which the equipment used may be simpler and more easily adjusted to operate on different sizes of envelope blanks.

It is also an object of this invention to provide a method of cutting notches in a succession of blanks in which only a single pair of cutters are required to remove the triangular chips from both the leading and trailiu edges of the blanks.

With the above and other objects in view, the invention comprises the several steps, sequences, devices, combinations, and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings, from which the several features of the invention and the advantages attained thereby will be readily understood.

In the accompanying drawings:

FIGURE 1 is a plan view, illustrating schematically the envelope making method of this invention, but omitting, for the sake of clearness certain structural components.

FIGURE 2 is an elevation view of FIGURE 1.

FIGURE 3 is a schematic view in plan illustrating steps of formation of conventional web cut diagonal seam envelopes.

FIGURE 4 is a schematic plan view of the method according to the present invention illustrating side-by-side, the method being used in conjunction with two different sizes of envelope blanks.

FIGURE 5 illustrates in a plan view a pair of smaller envelope blanks superimposed over a pair of larger envelope blanks, showing the manner in which a single pair of cutters is utilized in cutting the notches in the trailing edge of a leading blank, and in the leading edge of a trailing blank at the same time.

This invention achieves extremely high rates of production in the manufacture of the diagonal seam envelopes, especially with the rhombic or diamond shaped web-cut blanks, illustrated at E, E in the drawings' Each blank E, as shown, includes four edges 10, 12, 14 and 16, and is of a generally rhombic configuration. The web-cut blanks are cut successively from the leading end of an advancing web 18 of paper (see FIGURE 3). Upon severance from the web 18, the blanks E are immediately advanced in a direction parallel to one diagonal of the diamondshaped blank for subsequent scoring, notching, trimming, folding, and receiving gum. The blanks are advanced in a manner such that edges 10 and 12 are leading, and edges 14 and 16 are trailing. The present invention involves the cutting of the triangular shaped chips 20, 22, 24, and 26 from the marginal portions of the blanks E, to form the notches 28, 3t 32, and 34 at intermediate locations along the respective edges 10, 12, 14, and 16.

After the notches 28, 3G, 32, and 34 have been cut, the blanks are rapidly advanced further along the machine for making the score lines 35, 38, 40, and 42, which intersect at the apex of the notches. Thus when the triangular flaps are folded to form the back panel of the envelope, each of the folds are made through one thickness only of the blank.

As the envelope blanks E are cut from the end of the web 18, the spacing, or distance between transverse diagonals of the adjacent blanks, is determined and governed in a manner such that the distance bet-ween the trailing edge of the leading blank and the leading edge of the trailing edge, at the position where the notches are to be removed, is fixed. To this end, there is provided suitable feed rolls 44, and 44 which accept the blanks E from other parts or portions of the machine (not shown) and which are rotating at a speed relative to the feed rolls 46 and 46' so as to cause the blanks to assume a fixed spacing between transverse diagonals. The feed rolls 46 and 46 rotate at the same speeds, and the feed rolls 44 and 44' are appropriately relieved, as shown at 48, 48 in FIGURES l and 2, so as to release each blank E substantially at the instant the edges 10 and 12 encounter and are seized by the feed rolls 46 and 46. The set of feed wheels 46 and 46 adjacent the feed wheels 44 and 44 are made adjustable towards and away from the feed wheels 44 and 44 to accommodate the spacing to blanks of greater or less dimension, measured in the direction of their travel through the mechanism. Thus, with feed rolls 44 and 44' relieved at the portions 48 and rotating at a redetermined speed, the incoming blanks B will be seized .t a predetermined time, and with the set of feed rolls 3-6 and 46 rotating at a predetermined speed relative to the eed rolls 44 and 44', and at a predetermined distance way (as determined by adjustment thereof in the direcion of arrow X in FIGURE 2), the spacing of the adja- :ent blanks will be determined between the sets of feed 011$ 44, 44 and 46, 46'. This spacing is maintained by :ach of the sets of cooperating feed rolls 46, 46' until he blanks E are fed past the notch cutters.

For cutting the notches from the blanks, there is prolided a pair of cutters 50 and 52, each of which rotate rbout about an axis substantially parallel to the direction 3f feed of the blanks E. Such cutters are well known in ;he art. Briefly, the cutters 50 and 52 are mounted on shafts 54 and 56 respectively. Shaft 54 is rotatably mounted in frame members 58 and 60 by suitable bearings. Likewise, shaft 56 is rotatably mounted in frame members 62 and 64 by suitable bearings. Drive gears 66 and 68 are fixed to shafts 54 and 56 respectively, and are driven from a suitable power source (not shown). Frame members 58 and 60 are mounted on base plate 7 ii, and may be adjusted in-and'out (transversely to the path of blank movement) by means of the elongated adjustment slots 72 and 74 in base plate 70. Likewise, frame members 62 and 64 are mounted on base plate 76, and may be adjusted in-and-out by means of the elongated adjustment slots 73 and 80 in base plate 76. Suitable means for loosing and tightening the frame members 58, and 60 to base plate 70, and frame members 62 and 64 to base plate 76 are provided, e.g. the nuts 32 and 84 on the frame members 62 and 64.

The cutters 50 and 52 rotate together in synchronism with the timing of the blanks E passing through the machine. Suitable anvil means (not shown) are also provided next to the path of the blanks E and in position for cooperation with the cutting edges 86 and 88 of the cutters 50 and 52 respectively, so that when the cutting edges 86 and 88 pass the anvil means, a cutting action is rendered therebetween. Obviously, the anvil means must also be adjustable with in-and-out adjustments of the cutters 50 and 52 so as to always maintain a cutting relation between the cutters and the anvils. Such cutters (sometimes referred to as flying cutters) are so well known in the art that it is believed that the foregoing brief description will suflice.

The ratio of blank movement to revolutions of the cutters 50 and 52 is 1:1. The timing of the blank feed and angular position of the cutters 50 and 52 is such that the cutters 50 and 52 will cross the path of the blanks E approximately midway between the transverse diagonals of two adjacent blanks. Relative timing of the cutters 50 and 52 to the position of blanks E moving through the machine such that the corners 86 and 88 strike the blanks E in the correct place for removing the triangular notches 20, 22, 24 and 26.

FIGURE 4 illustrates the feeding of two different sizes of blanks E through a portion of the envelope making machine, illustrating how the spacing of the blanks, or distance between transverse diagonals of adjacent blanks may be determined to result in a spacing between the trailing edges 14 and 16 of a leading blank E, and the leading edges and 12 of a trailing blank E to fit the size and shape of the cutting edges 86 and 88 of the cutters 50 and 52 respectively. The spacing of the blanks B may conveniently be determined by the first set of feed rolls 44 after the blanks are severed from the end of the web 18, and maintained in proper spaced relation by the feed rolls 46 and 46'. In FIGURE 4, the blanks E on the right side are obviously smaller than the blanks E on the left side. However, both rows of blanks, regardless of their size are spaced apart a predetermined distance so that the distance between the trailing edges 14 am 16 of the leading blanks, and theleading edges 10- and 12 of the trailing blanks, at the position of the notches to be removed, are spaced apart the same distance d. In this manner, the notches in the blanks, regardless of the size of the blanks, may be cut with a fixed-size single pair of cutters.

In FIGURE 5, there is illustrated two adjacent small size blanks E, E superimposed over two adjacent large size blanks, E, E. As illustrated in this drawing the blanks E, E and E, E are spaced, regardless of size and shape, so that the notches to be cut from the edges are a fixed distance apart in the succession of blanks. Only the outline of the cutting edges 86 and 88 of the cutters 50 and 52 respectively is shown for the sake of clarity. The single pair of fixed size cutters having cutting edges 86 and 88 may easily be used to cut the desired notches. The corners 86 and 88 of the cutting edges 86 and 83 are of a predetermined shape so as to cut out the triangular chips 20, 22, 24-, and 26.

In practice, the method according to this invention is carried out by adjusting the speed of the feed rolls 44 and 44 relative to the speed of the feed rolls 46 and 46' so that the correct spacing of the blanks E is attained for cutting the notches in the edges thereof by means of the single pair of fixed size cutters 50 and 52. Transverse spacing of the cutters 5i) and 52 and the corresponding anvils (not shown) are adjusted transversely to the path of blank movement by moving the frame members 58 and 60 holding cutter 50, and frame members 62 and 64 carrying cutter 52, in or out in the b direction, according to the size blanks E to be notched. The speed and timing of the cutters 50 and 52 are then adjusted for cutting the notches from the trailing edges 14 and 16 of a leading blank, and the leading edgeslt) and 12 of the adjacent blank.

It will be understood that various changes in the details, materials, steps, and arrangements of par-ts, which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the scope of the invention as expressed in the appended claims.

I claim:

1. In the removal of substantially triangular chips from the leading and trailing marginal areas of envelope blanks advancing in aligned relationship to make the blanks foldable into an envelope, the method of using cutters of fixed configuration to remove the chips from various sizes of blanks which comprises the steps of (a) adjusting the position of the cutters transversely of the direction of blank movement for a given size blank,

(b) gaging the distance between adjacent blanks such that the chips to be removed from the trailing edge of a leading blank and the leading edge of the adjacent trailing blank are spaced apart a predetermined distance, and

(c) passing the blanks through the cutters in timed relation to the operation thereof such that portions of the cutters remove chips from the trailing edges of the leading blanks, and other portions of the cutters remove chips from the leading edges of the trailing blanks.

2. In the removal of substantially triangular chips from a the leading and trailing marginal areas of substantially rhombic shaped envelope blanks advancing in aligned relationship to make the blanks foldable into an envelope, the method of using a pair of cutters of fixed configuration to remove the chips from various sizes of blanks which comprises the steps of (a) adjusting the position of the cutters on each side of the path of the blanks transversely of the direction of blank movement for a given size blank, (b) gaging the distance between adjacent blanks such that the chips to be removed from the trailing edge of a leading blank and the leading edge of the adjacent trailing blank are spaced apart a predetermineddistance, and

5 6 (c) passing the blanks through the cutters in timed relationship in a direction parallel to one diagoni relation to the operation thereof such that portions of the blanks, the spacing between adjacent blanl of the cutters remove chips from the trailing edges being such that the chips to be removed from tl: of the leading blanks, and other portions of the trailing edge of a leading blank and the leadin cutters remove chips from the leading edges of the 5 edge of a trailing blank conforms to the size of th trailing blanks. cutters, and 3. In the removal of substantially triangular chips from (c) passing the blanks past the cutters in synchronisr the leading and trailing marginal areas of substantially withth operation ofthe cutters, rhombic shaped envelope blanks, the method of using a pair of cutters of fixed configuration to remove the 10 References Cited chips from various sizes of blanks which comprises UNITED STATES PATENTS the ste s of (a) adjusting the position of each of said cutters 0n 1572110 2/1926 Duvau 83-45 each side of the path of the blanks transversely of 2,696,255 12/1954 Heywood- 3:11: nlillI'CCtlOIl of blank movement for a given size 15 WILLIAM W DYER, JR. Primary Examiner.

(b) advancing the blanks in equally spaced and aligned JAMES M. MEISTER, Examiner. 

2. IN THE REMOVAL OF SUBSTANTIALLY TRIANGULAR CHIPS FROM THE LEADING AND TRAILING MARGINAL AREAS OF SUBSTANTIALLY RHOMBIC SHAPED ENVELOPE BLANKS ADVANCING IN ALIGNED RELATIONSHIP TO MAKE THE BLANKS FOLDABLE INTO AN ENVELOPE, THE METHOD OF USING A PAIR OF CUTTERS OF FIXED CONFIGURATION TO REMOVE THE CHIPS FROM VARIOUS SIZES OF BLANKS WHICH COMPRISE THE STEPS OF (A) ADJUSTING THE POSITION OF THE CUTTERS ON EACH SIDE OF THE PATH OF THE BLANKS TRANSVERSELY OF THE DIRECTION OF BLANK MOVEMENT FOR A GIVEN SIZE BLANK, (B) GAGING THE DISTANCE BETWEEN ADJACENT BLANKS SUCH THAT THE CHIPS TO BE REMOVED FROM THE TRAILING EDGE OF A LEADING BLANK AND THE LEADING EDGE OF THE ADJACENT TRAILING BLANK ARE SPACED APART A PREDETERMINED DISTANCE, AND (C) PASSING THE BLANKS THROUGH THE CUTTERS IN TIMED RELATION TO THE OPERATION THEREOF SUCH THAT PORTIONS OF THE CUTTERS REMOVE CHIPS FROM THE TRAILING EDGES OF THE LEADING BLANKS, AND OTHER PORTIONS OF THE CUTTERS REMOVE CHIPS FROM THE LEADING EDGES OF THE TRAILING BLANKS. 